1. Field of the Invention
The present invention relates to a rolling guide apparatus suitable for use as, for example, a rolling guide having a mounting surface of poor accuracy for an aseismatic or quake-free device of a relatively small-scale building, or for use as a rolling guide adapted to be mounted on a part or object which is moving at high speed, such as a motor vehicle, an airplane or the like, and which can be deformed at any time due to a shock or impact applied thereto.
2. Description of the Related Art
Conventional rolling guide apparatuses are mainly used for linear guiding parts of a machine tool to achieve guidance with high accuracy while supporting heavy loads by their highly rigid structures.
In contrast to this, the inventor has already proposed a roller guide apparatus in Japanese patent application laid-open No. 2000-291653 (see FIG. 25), which comprises a track rail 1000 provided with projected portions 1020, 1020 projecting laterally or to the left and right from a rail base portion 1010 of high rigidity, and a movable block 3000 having at least four sets of endlessly circulating roller rows 2000 built therein which are in rolling contact with the upper and lower surfaces of the left and right projected portions 1020, 1020 of the track rail 1000, wherein when an impact or shock load acts on the apparatus in a vertical direction, the impact or shock load acting on rolling members is absorbed by elastic deformation of the projected portions 1020, 1020 in such a manner that an impact of 3G is reduced to about 2G, for instance,
The track rail projected portions 1020 are each of a circular arc shape, and barrel-shaped rollers 2001 are used for the endlessly circulating roller rows 2000 which are in contact with the upper side circular-arc concave surfaces, and hourglass-shaped rollers 2002 are used for the endlessly circulating roller rows 2000 which are in contact with the lower side circular-arc convex surfaces, thereby ensuring self-aligning capability of the apparatus to permit the barrel-shaped and hourglass-shaped rollers to slip sideways along the circular arc shapes of the track rail projected portions 1020, respectively.
However, the above-mentioned conventional rolling guide apparatus includes the thick and highly rigid rail base portion 1010 and is heavy in weight, so there has been a problem that such a rolling guide apparatus is not suitable for use with motor vehicles, aircrafts and the like requiring weight reduction, and hence the applications of use thereof are limited.
In addition, though shock or impact can be absorbed by the elastic deformation of the track rail projected portions 1020, such shock or impact is assumed to be an impulsive or severe up-and-down shake of a massive earthquake, and hence the conventional rolling guide apparatus basically has high rigidity, and the projected portions 1020 can be elastically deformed only when subjected to a large shock or impact load.
Moreover, even if it is said that the apparatus has self-aligning capability, the movable block 3000 is swung along the circular arc shapes of the track rail projected portions 1020, so that a parallelism error between a mounting surface of the movable block 3000 and a mounting surface of the track rail 1000 can only be absorbed, but a lateral or transverse error of the mounting surface of the track rail 1000, a parallelism error in the vertical direction, etc., can not be accommodated. Accordingly, some. degree of accuracy is needed for the mounting surfaces, and hence the fields of use of the apparatus are limited.
The present invention has been made to solve the problems as referred to above, and is intended to provide a rolling guide apparatus which is reduced in size and weight, but of course has the function of absorbing shock or impact load, and which is provided with a track rail of a flexible structure capable of automatically adjusting an error between the mounting surfaces of the track rail and a movable block.